> There's an issue with the following XML file, which does not have
> any special character, except a single quote in the middle of the
> text.
>
> <root>
> <a>12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789'012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
> </a>
> </root>
>
> Note that the newline character before the </a> is important.

Right, this is due to chunking by syntax-propertize.  Here's the fix: